I have a 2004 PS 197 that I purchased that needs some work. I am currently rebuilding the engine and I am looking for some help finding some parts. I am looking for two standard bore pistons GM part # 10172839. I am also in search of an intake, my engine has the the anodized red multi-port fuel injetion. The water ports on the intake have heavy corrosion from salt water I am assuming. I was hoping maybe somebody out there in the MC community has some parts from a damaged 5.7 MCX engine. If anyone has any source for parts new or used I would appreciate the help. I am having trouble identifying parts for my engine. For example if I want to buy a replacement set of pistons what would I buy? the GM #10172839 pistons have a coated skirt and smaller rings, anyone familiar with this? Any help would be appreciated.

Rossterman

06-17-2012, 12:26 PM

Would suggest you put a fresh bore in it and new set of pistons. Marine engine doesnt use anything special so you just need to make sure to get the right size and piston top configuration to maintain same compression ratio. Looking quickly, it seems they use .100 dished piston with 4 valve reliefs. Piston kit (hyperutectic w/ good moly rings) from sealed power is only $149 complete from summit racing.

It would be a shame to put back together just changing a few pistons and having a worn motor vs. freshened lower end that performs like a new motor for only a few $more. Heck, i'd probably check rod and main bearing clearance while apart and throw new bearings it it too as less than $100 for all new sealed power bearings.

Typically folks do a that kind of repair (replacing a piston or 2) when they are planning on selling it and not advertising a rebuild motor to minimize spending money and reducing their profit. Wasn't sure if you bought it to fix up and resell but if you are planning on keeping it, this would be money well spent.

NoWake197

06-18-2012, 12:29 AM

The engine (<200 hrs) took on water and was put away with water in cylinders 4 & 6. The standard bore is in good shape but these two pistons have some pitting above the top compression ring. The other 6 pistons look like new. This GM piston has the 1.5 mm top, 1.5 mm second, with a 3.0 mm oil ring. This is a very low-tension ring pack that works very well on oil control and cylinder sealing. This piston and ring pack is a major upgrade to the standard slipper skirt, 1/16-, 1/16-, 3/16-inch ring package. I am planning on keeping the boat for my family. I was just hoping someone may have some parts sitting around from an MCX engine.

Rossterman

06-19-2012, 12:30 AM

OK that explains your strategy better. If bores are clean and no significant pitting wear a ball hone to refinish and a couple of new pistons/rings and should be good to go.